Slipped Capital Femoral Epiphysis at Young Age Predicts Bilaterality

Abstract

Source: Riad J, Bajelidze G, Gabos PG. Bilateral slipped capital femoral epiphysis: predictive factors for contralateral slip. J Pediatr Orthop. 2007.27;411–414.Slipped capital femoral epiphysis (SCFE) is characterized by instability of the proximal femoral growth plate. Investigators from the Alfred I. duPont Hospital for Children in Wilmington, Delaware, sought to determine predictors of contralateral slip in children with unilateral SCFE. The authors retrospectively reviewed the records of 235 patients with SCFE seen between 1990 and 2002. Children were excluded from analysis if they had bilateral disease on initial presentation, had incomplete radiographic data, were treated previously or elsewhere, had known endocrinopathies, or experienced comorbidities necessitating prophylactic screw fixation.The authors identified 70 patients with unilateral disease at presentation. Of these, 16 (23%) went on to develop bilateral disease. The mean age of both boys and girls who later developed bilateral SCFE was less than the mean age of those who did not develop bilateral disease (11.0 vs 11.9 for girls and 12.1 vs 14.2 for boys): 25% of girls younger than 12 years and 37% of boys younger than 14 years developed a contralateral slip. All girls younger than 10 (n=2) and boys younger than 12 (n=5) developed bilateral disease. Bivariate and subsequent multivariate correlation demonstrated a significant association between the development of contralateral SCFE and age (P<.01). For every one year increase in age at initial presentation, the patients were less likely to develop a contralateral slip (OR=.344). The authors conclude that in girls younger than 10 and boys younger than 12 years of age who present with unilateral SCFE, contralateral prophylactic screw fixation should be strongly consideredDr. Raszka has disclosed no financial relationship relevant to this commentary. This commentary does not contain a discussion of a commercial product/device. This commentary does not contain a discussion of an unapproved/ investigative use of a commercial product/device.SCFE is one of the most common adolescent hip disorders. Boys are more commonly affected than girls.1 Several studies have demonstrated that between 40% and 80% of those who present with unilateral SCFE go on to develop bilateral disease.2–3 Reported predictive factors for contralateral involvement include sex, chronologic age, bone age, race, and obesity, although only age and skeletal maturity were looked at specifically in this study.4–5 Predicting who will develop contralateral disease has important implications for follow-up or the use of prophylactic fixation at the time of surgery for the involved hip. However, data accurately predicting who will develop bilateral disease are lacking.Clinical decision analysis models have reached different conclusions about whether to perform prophylactic fixation because of different assumptions about the risks of developing contralateral disease.6–7 This study adds to the body of evidence that suggests young age at presentation is a risk factor for bilateral SCFE. Unfortunately, the authors could not evaluate the relative contribution of body mass index to the risk of SCFE development as height, and even weight, were often not recorded. Based on this and other studies, the younger the child at the time of presentation with SCFE, the more seriously prophylactic fixation of the uninvolved side should be entertained. Children with SCFE, particularly young adolescents, need to be monitored for contralateral involvement with serial examinations and radiographs.